1. Field of the Invention
The invention pertains broadly to the field of charged particle accelerators. More particularly, but without limitation thereto, the invention relates to an optically powered high voltage electron accelerator.
2. Description of the Related Art
Over the years the production and adequate control of high voltage charged particle beams has prove to be increasingly useful. For example, ion beams are commonly used in the semiconductor industry. Here, an ion beam contributes to the sputtering or implantation of various elements during the course of semiconductor production. Electron beams have proven their usefulness in radiation simulation and in electron microscopy.
To generate either ion or electron beams, high voltage power is necessary to provide beam current and accelerating bias. For example, in electron microscopy electron accelerating voltages range anywhere from a few hundred to a million volts. High accelerating voltages have proven useful for high resolution transmission electron microscopy.
In a typical charged particle accelerator a number of accelerating "stages" may be used to provide desired particle acceleration. Each of these stages are voltage biased to create an accelerating force for a charged particle such as an electron. One form of charge particle accelerator employs static bias voltages.
Various techniques for providing necessary voltages to the accelerating stages are available. Typically, heavily insulated cables are passed from a power source into a vacuum chamber that houses the accelerating stages.
To adequately control the production of charged particles such as electrons it is necessary to maintain a charged particle control device within a vacuum; however to pass cables into the vacuum without allowing unwanted current flow due to breakdown effects becomes increasingly difficult when higher voltages are used.
In an alternative arrangement, a charged particle accelerator may incorporate a power generating source or sources within a vacuum chamber. The invention described herein teaches such an arrangement.